where ILTR is the cancer risk; ED is the exposure duration (year); EF is the exposure frequency (day); BW is the body weight; LE is the life expectancy of the exposed person (day); CSF (cancer slope factor) is the oral cancer slope factor for iAs (per mg/kg/day) (ATSDR (Agency for Toxic Substances and Disease Registry), 2010 and USEPA (United States Environmental Protection Agency), 2010).